Play with your magnets!. ALL magnets have two poles NORTH seeking pole SOUTH seeking pole.
-
Upload
angelina-trujillo -
Category
Documents
-
view
215 -
download
0
Transcript of Play with your magnets!. ALL magnets have two poles NORTH seeking pole SOUTH seeking pole.
Play with your magnets!
ALL magnets have two poles
NORTH seeking pole
SOUTH seeking pole
Breaking a magnet produces two magnets!
N S
N S
NN SS
Opposites attract!
Opposite poles attract and like poles repel
Magnetic materials
Magnetic materials
Iron (steel), Cobalt and Nickel
Magnetic induction
Magnetic induction
When a magnetic material is close to a magnet, it becomes a magnet itself
We say it has induced magnetism
NS
NSmagnet
Hard and Soft Magnetism
Soft Magnetism
Pure iron is a soft magnetic material
It is easy to magnetise but loses its magnetism easily
NS
before after
Iron nail
SN
NS
Not a magnet
N
Hard Magnetism
Steel is a hard magnetic material
It is harder to magnetise, but keeps its magnetism (it is used to make magnets!)
NS
before after
Steel paper clip
NNS
It’s a magnet!
N
S
S N
Magnetic field
I wonder if this is a magnetic
field?
Magnetic field
Magnets (and electric currents) produce magnetic fields around them.
In the magnetic field, another magnet or magnetic material will experience a magnetic force.
Magnetic field lines
We can represent the magnetic field around a magnet using field lines.
Magnetic field lines
The arrows show the direction a compass needle would point at that point in the field.
Magnetic field lines
The closer the field lines are, the stronger the magnetic force felt
The arrows show the direction a compass needle would point at that point in the field.
Earth’s Magnetic Field
N
S
Remember the North of a compass needle points to the geographic north pole (i.e. the geographic North pole is a magnetic south pole!)
Field around a bar magnet
Two bar magnets
Strong uniform field
Two bar magnets
no field!
That’s it!
Mind-map
Mr Porter is now going to put these slides on a loop and you’re going to mind-map them!
This lesson
• ac/dc
• Insulation and double insulation
• Earthing, fuses and circuit breakers
• Formative assessment
Gather round!
Reading!
• Read carefully pages 192-195
• Answer the questions on both pages
• Finish for homework due Tuesday 13th January